The changes started coming slowly ...

First was the lettering on the pavement -- "Canada" on one side, "U.S.A." on the other. Then came the white pylons. After that, signboards were erected on some streets, ordering drivers to turn back and use an officially designated entry point.

For longtime residents accustomed to a simpler life that flowed freely across a largely invisible border, the final shock -- and what made most people really take notice -- was a proposal by the border agents last year to erect fences on the small streets to officially barricade the United States from Canada, and neighbor from neighbor.

A large part of the job, border agents said, is community outreach and educating border residents that the way of life they have known for generations has profoundly changed.

Beltran said he instructs his agents to use discretion and "common sense." It goes like this: "If a kid [on the Canada side] throws a Frisbee over here, he can come and get it. But if he got the Frisbee and kept walking down to the Arby's to get a soda, we're going to stop you."

"We can't be wrong once."

From the archive:

"You can't talk sense to them," Bush said, referring to terrorists.

"Nooooo!" the audience roared.

Decius:

Overestimating the threat, when you're lining people up against the wall without due process, does have a cost, and frankly it's your soul.

Final thoughts:

According to one who was present, Churchill suddenly blurted out: "Are we animals? Are we taking this too far?"

People say to me, "Whatever it takes." I tell them, It's going to take everything. And still I see a woman in row four, cutting an apple. With a four-inch knife.